This invention relates to shot columns.
Existing buckshot cartridges have a distinct disadvantage at long (beyond 50 meters) ranges. A loss of sphericity is a principle cause of pattern spreading. It also induces a high drag coefficient which slows down the buckshot.
Unprotected shot becomes deformed when subjected to high accelerations mainly because the bottom shot pellets are literally crushed by accelerative forces exerted by those pellets above and around them. The shot on the bottom layer deforms more than that on the top layer. Crushed shot is less spherical and thus travels more erratically and slows down quicker. Less uniform shot travels less uniformly.
It is well known that increasing the hardness of the shot, such as by alloying antimony with the lead shot, increases the hardness of the shot and reduces shot deformation. This harder shot gives more uniform patterns at longer ranges because more uniform shot travels more uniformly. The addition of a buffering material, such as granular polyethylene, as found in premium loads currently manufactured by all three of the leading shotshell manufacturers after having been originated by Winchester, has been shown to have significantly beneficial effects because the buffering material is deformed before the lead shot. Alloying and buffering seek to better preserve the initial spherical shape of the shot from the time it is fired until it exits the barrel muzzle.
Two additional beneficial approaches to reducing shot deformation were also originated by Winchester. First was the plating of copper upon the softer lead in order to give more hardness and a better aesthetic appearance. Second was the development of a plastic shot collar to surround the shot and protect it from abrasions during its travel down the barrel bore.
Nevertheless, it is widely recognized by industry experts that the current effective range of 000 buckshot is about 50 meters even with the premium loads such as Winchester Super Double X Magnum premium shotshell loads. As was the case back in 1921 when John Olin developed the Super-X extended range shotshell to be able to out-distance his duck hunting friends, present day shotshell designers continue to look for ways of extending the effective range of shot.
This invention further minimizes shot deformation and thus extends the effective range of shotshells by providing a saboted shot.